1. Field
Embodiments relate to a secondary battery.
2. Description of the Related Art
Fossil fuel vehicles, e.g., gasoline-powered and diesel-powered vehicles, are major sources of air pollution. In recent years, environmentally friendly vehicles, e.g., electric vehicles and hybrid-electric vehicles, have attracted much attention as alternatives to conventional fossil fuel vehicles. Batteries may be used to drive motors of electric or hybrid vehicles. For this purpose, secondary batteries, which may be convenient and easy to charge, are currently used.
Secondary batteries may be capable of repeated charge/discharge cycles. Secondary batteries may be typically classified into two types, cylindrical and prismatic, depending on their shape. Prismatic batteries may be safer against overcharging than cylindrical batteries due to, e.g., more efficient heat dissipation. However, the high capacity required in a prismatic battery for a vehicle, e.g., a hybrid vehicle, may involve an increase in the size of the prismatic battery. Such an increase in size of the prismatic battery may result in an increase in the thickness of the prismatic battery, which may in turn cause a difference in heat dissipation between inner and outer portions of the prismatic battery. This difference in heat dissipation may make it difficult to dissipate heat from the battery. Therefore, the prismatic battery may become unsafe when overcharged. Thus, an improved structure of the prismatic battery may ensure safety.